Spread across the two days of last weekend, we managed to complete the low level roof, making 2 out of 3 bits of roof now waterproof. Whilst waiting for the expanding foam spraycan to warm up we started battening out this wall: Work in progress on the roof, here you can see we've stripped away the Tyvek on the wall in order to stick the EPDM to it as an upstand, and then later we put the Tyvek back over the top of the upstand we'd just created - making a waterproof detail. Pay particular attention to Emma's camp pose:

Yes that is ice, and yes is it a good thing that our glue isn't water-based!

I now have my van back, and we were able to go to Cotswold Efficient Energy Centre yesterday morning, where we discussed various things about heat pumps. They recommend the Mitsubishi unit over the Worcester Bosch one, but a company called Grant are apparently set to release one in January which promises to be even better! So I think we'll leave this decision until next year.